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Wildlife is largely managed by states, which have primary responsibility for managing hunting, fishing, and the health of their state’s wildlife, including managing invasive species. The federal government plays a significant role by regulating and protecting threatened and endangered species through the Endangered Species Act (ESA), the Marine Mammal Protection Act, and the Lacey Act . The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and the Convention on Biodiversity (CBD) are the main international treaties that provide protection for endangered species.

For a discussion of state protection of biodiversity, see Susan George, State of the States: An Overview of State Biodiversity Programs. States use wildlife action plans to guide their management efforts. Several ELI research reports discuss these plans and efforts to mitigate impacts of development on wildlife. For a 2007 workshop and various materials on integrating state wildlife plans and wetlands protection, see this page.

For a thorough discussion of the federal endangered species act, see Lawrence Liebesman, Endangered Species Act Deskbook, 2d ed.

ELI has a significant research program devoted to biodiversity preservation—with many projects ongoing and an extensive body of research reports.

Lacey Act

The Lacey Act is the oldest national wildlife protection statute in the United States, enacted in 1900. The Lacey Act regulates and prohibits trade in certain wildlife and plants that have been possessed, transported or sold in violation of state or federal law or treaty, and the falsification of documents or the failure to mark wildlife and plant shipments. The Act was broadened in 2008 to apply to a broader range of plants and plant products, including timber. The Act has a variety of sanctions for violations, including civil or criminal penalties, permit revocation, or forfeiture of wildlife, plants and equipment used in trafficking.

For a general discussion of the Lacey Act, see Law of Environmental Protection, §23.67.  For a 2012 seminar on strengths and weaknesses of the Lacey Act, see The Lacey Act and ‘Imported Plant Products For a 2009 seminar on the 2008 amendments to the Lacey Act, see Lacey Act Amendment—New Due Diligence Requirements Regarding Source of Wood in Products.

Endangered Species Act

The ESA was passed by Congress in 1973 as a response to the emerging awareness of the importance of biodiversity and concern surrounding the alarming rate of decline of many species. It was the intention of Congress to use the ESA to stop and reverse the trend towards species extinction. The purpose of the statute is threefold: to provide a means to conserve ecosystems of endangered and threatened species, to provide conservation programs for endangered and threatened species, and to take appropriate steps to achieve the purposes of other treaties and conventions identified in the ESA.

For a primer on the ESA, watch and download materials from the ELI Summer School program NEPA, ESA and the Fundamentals of Environmental Law.

Many commenters agree the ESA can be improved, but just how to make these improvements remains controversial. For a sampling of the discussion, see Jason Rylander, Recovering Endangered Species: Can the ESA Go Beyond Mere Salvage?; Don Baur, Michael Bean & William Irvin, A Recovery Plan for the Endangered Species Act; J.B. Ruhl, Climate Change and the Endangered Species Act: Building a Bridge to the No-Analog Future; Katrina Wyman, Rethinking the ESA to Reflect Human Dominion over Nature; and Jason Totoiu, Building a Better Endangered Species Act: An Integrated Approach Towards Recovery.

The U.S. Department of the Interior is responsible for implementing and carrying out provisions of the ESA for terrestrial species through the US Fish and Wildlife Service, while the U.S. Department of Commerce implements both the ESA and the Marine Mammal Protection Act to oversee marine species and certain species of migrating fish through the National Marine Fisheries Service.

For a discussion of the ESA and MMPA in action, see Koalani Laura Kaulukukui, The Brief and Unexpected Preemption of Hawaii’s Humpback Whale Laws: The Authority of the States to Protect Endangered Marine Mammals under the ESA and MMPA.

The ESA describes how to determine and designate a threatened or endangered species, how to designate protected habitat for such species, how to create a recovery plan for the species, how federal agencies must consult with other agencies about listed species, which acts involving listed species, such as takings, are prohibited, and how to enforce the provisions and penalize violators.


The Fish and Wildlife Service and National Marine Fisheries Service publish lists of wildlife and plant species determined to be “threatened” or “endangered.” A species is considered “endangered” when it is danger of becoming extinct “throughout all or a significant portion of [its] range,” while “threatened” species are those that will likely become endangered in the foreseeable future. A species may be listed due to any of the following factors:

  1. The present or threatened destruction, modification, or curtailment of a species’ habitat or range;
  2. Overutilization for commercial, recreational, scientific, or educational purposes;
  3. Disease or predation;
  4. The inadequacy of existing regulatory mechanisms;
  5. Other natural or manmade factors affecting its continued existence.

Only the best scientific data available are considered; potential economic impact may not be considered. The services are supposed to review listings every five years to determine whether a species should be removed, upgraded, or downgraded from the lists.

Anyone may petition to have a species listed as endangered or threatened. When such a petition is submitted, the agency is required to make a finding and respond within 90 days.

With the recovery of some species, many questions are being asked about delisting endangered species under the ESA. For example, see Edward Fitzgerald, Delisting Wolves in the Northern Rocky Mountains: Congress Cries Wolf and Federico Cheever, The Rhetoric of Delisting Species under the ESA: How to Declare Victory without Winning the War.

Critical habitat

Once a species is listed as threatened or endangered, the agencies designate an area of critical habitat. Critical habitat is defined as the “specific areas within the geographical areas occupied by the species, at the time it is listed . . . on which are found those physical or biological features (I) essential to the conservation of the species and (II) which may require special management considerations or protection . . . .” Designation of critical habitat only affects activities that involve a federal permit, license, or funding and are likely to destroy or adversely modify the critical habitat. It does not impact private actions or necessarily restrict further development. Unlike the listing process, agencies must take economic considerations into account when designating critical habitat.

For a discussion of the interplay between development and critical habitat preservation, see the ELI research projects Mapping High-Risk Critical Habitats and Naturally Green Planning Research and Policy Analysis.

As environmental law continues to evolve, trading of habitat is being used to reduce economic burden and find greater efficiency. See, for example, Michael Bean et al., Design of U.S. Habitat Banking Systems to Support Conservation of Wildlife Habitat and At-Risk Species Jonathan Remy Nash, Trading Species: A New Direction for Habitat Trading Programs, with responses by Virginia Albrecht and Michael Bean.

Recovery plans

Recovery plans must be adopted and implemented for all listed species, unless there is a finding that a plan will not benefit the species. Recovery plans are drafted by teams comprised of citizens, government representatives, and members of the scientific and academic community and may apply to more than one species. The recovery plans should:

  1. Describe any site-specific management actions necessary to conserve and ensure survival of the species;
  2. Identify objective, measureable criteria that should result in the delisting of the species; and
  3. Set time and cost estimates for the carrying out of plan measures and to achieve intermediate steps toward the goal of recovery.

These criteria act as guidelines, not specific requirements, and agencies have significant freedom in determining if and when recovery plans are created. The plans should take economic and social impacts into account. Recovery plans do not have the force of law, and courts generally decline to enforce the plans.

Federal agency consultations

Federal agencies must protect and conserve listed species so that federal agency action “is not likely to jeopardize the continued existence of any endangered species or threatened species or result in the destruction on adverse modification of habitat of such species.”

Before engaging in any activity that may have direct or indirect effects on listed species or critical habitat, federal agencies must consult with the NMFS or FWS to evaluate the potential impact of the proposed action. This is commonly referred to as the “consultation process” and includes any action that is “authorized, funded, or carried out, in whole or in part, by Federal agencies.”

For a discussion of interagency consultation procedures, see Cynthia Drew, Beyond Delegated Authority: The Counterpart Endangered Species Act Consultation.

Takings and prohibited actions

It is illegal to “take” endangered species and certain threatened species. “Take” is defined as “to harass, harm, pursue, hunt, shoot, wound, kill, trap, capture, collect, or attempt to engage in any such conduct.” Almost anything that can have a negative impact on a species, in addition to actions or omissions that result in the injury or death of even a single member of a listed species, constitutes a takings under the ESA. In addition, for wildlife it is illegal to:

  1. Import or export of an endangered species;
  2. Possess, sell, carry, deliver, transport, or ship any endangered species unlawfully “taken” in the course of commercial activity;
  3. Engage in any activity involving interstate or foreign commerce in endangered species; and
  4. Violate any regulation pertaining to endangered or threatened species.

Congress has included certain limited exceptions to the prohibition against takings. Landowners may apply for an Incidental Take Permit under §10, which allows them to take a listed species “if such a taking is incidental to, and not the purpose of, the carrying out of an otherwise lawful activity.” In order to obtain an Incidental Take Permit, a landowner must first submit a Habitat Conservation Plan that specifies the impacts of the take, the steps to be taken to minimize and mitigate such impacts, the funding available, and the alternatives, including reasoning for why alternative actions are not being pursued.

For a discussion of incidental take permits in action, see Patrick Duggan, Incidental Extinction: How the ESA’s Incidental Take Permits Fail to Account for Population Loss.

A Safe Harbor Agreement also provides a route around the prohibition on taking. Under such an agreement, a landowner engages in activities that may restore, enhance, or maintain habitat for a listed species on private land. In exchange, the landowner receives guarantees that future land restrictions will be limited, and some incidental take may be allowed. Similar agreements known as Candidate Conservation Agreements and Candidate Conservation Agreements with Assurances are available for species that are candidates for listing, but as of yet have not been formally listed.

Enforcement and citizen suits

Penalties for violation of the ESA include civil and criminal penalties, injunctions, and loss of permits, licensees and federal leases. A violation affecting an endangered species is more severe (up to $25,000 fine per occurrence and potential criminal penalties of $100,000 and a year in jail) than those affecting a threatened species (up to $12,000 fine per occurrence and potential criminal penalties of $25,000 and six months in jail). Other violations may result in $500 fines, as well as seizure of guns, traps, nets, and other equipment, including vessels, vehicles or aircraft used to air in the violation.

The intent requirement for criminal violation of the ESA is that one “knowingly committed” an act. It is not necessary to show that an individual who killed an animal had knowledge that the species was endangered; all that is required is that the individual knew he or she was killing an animal. However, there is an exception to this rule when the individual can demonstrate that he or she acted “based on the good faith belief that he was acting to protect himself, or a member of his or her family, or another individual from bodily harm from any endangered or threatened species.”

For a discussion of enforcement of species protection, watch and download materials from the ELI seminar, Ocean and Coastal Law Enforcement: Enforcing Protected Species Laws in the Marine Environment.

Citizens may bring suit to enforce the ESA. The citizen suit provision gives private citizens the power to act as private attorneys general to sue in court for violations of the ESA. Citizens are authorized to commence a civil suit:

  1. To enjoin any person, including the United State and any other governmental instrumentality or agency (to the extent permitted by the eleventh Amendment to the Constitution), who is alleged to be in violation of any provision of [the ESA];
  2. To compel the Secretary to apply [section 4(d) or 9 prohibitions] with respect to the taking of any resident endangered species or threatened species within any State; or
  3. Against the Secretary where there is alleged a failure of the Secretary to perform any act of duty under [section 4 of the ESA] which is not discretionary with the Secretary.

While the citizen suit provision is interpreted broadly, an individual or group wishing to bring a suit must still satisfy the standing requirement.

For a discussion of how endangered species protection interacts with renewable energy facility siting, listen to and download materials from the ELI seminars Wind Energy, Wildlife, and Endangered Species and USFWS Wind Energy Guidelines Workshop.

Invasive Species

While endangered and threatened species garner most of the attention when discussing wildlife management, invasive species is a critical area as well. Invasive species pose a significant ecological, economic, and social threat to the United States. Stopping their introduction, eliminating their spread, and mitigating their impact are the thrust of current laws and policies, which remain somewhat underdeveloped and underfunded. As with wildlife management, most responsibility rests on the states, with the federal government playing mostly a coordinating role.

ELI has an extensive Invasive Species program and has published many research reports on the topic. ELI’s seminal report, Halting the Invasion: State Tools for Invasive Species Management, can be downloaded for free. Marc Miller’s Harmful Invasive Species: Legal Responses, outlines international responses to controlling this threat.

For a discussion of the links between climate change and invasives, download materials from the 2008 ELI Seminar Invasive Species and Climate Change: Risks and Responses.


The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) is an international agreement signed by more than 175 parties with the mission of protecting more than 30,000 threatened and endangered species from exploitation caused by unregulated international wildlife trade. CITES requires member countries to obtain permits for trading threatened or endangered species, with the threat of sanctions for failure to do so. The U.S. was the first signatory of CITES, in 1974. In the United States, CITES is implemented by the Fish and Wildlife Service, the Animal and Plant Health Inspection Service , and NOAA Fisheries

For a discussion of CITES, see Laura Kosloff, CITES: No Carrot, But Where’s the Stick?

An important aspect of the Convention on Biological Diversity is giving host countries and indigenous peoples rights to the genetic resources found and exploited in their countries and traditional homelands. A 2009 ELI seminar discussed these issues, and materials from the seminar are available for download here. The ELI Report African Perspectives on Genetic Resources: A Handbook on Laws, Policies, and Institutions can be downloaded for free.

The Convention on Biological Diversity seeks to protect the diversity of both wildlife and other living species around the globe. Although the United States signed the treaty in 1994, it has not ratified it. As a result, it is not in force in the United States.